Liquid displacement pumps



Aug. 5, 1969 R. T. J. SKINNER I 3,459,130

LIQUID DISPLACEMENT PUMPS Filed Feb. 28, 1967 US. Cl. 103-2 United States Patent M 3,459,130 LIQUID DISPLACEMENT PUMPS Robert Thomas John Skinner, Kenilworth, England, assignor to Joseph Lucas (Industries) Limited, Birmingham, England, a British company Filed Feb. 28, 1967, Ser. No. 619,351 Int. Cl. F041) 13/02; F04d 1/00 1 Claim ABSTRACT OF THE DHSCLOSURE A liquid displacement pump has a body, a rotor in a cavity in the body, a recess in the wall of the cavity between an inlet and an outlet, and an abutment adjacent to the outlet end of the recess being shaped so that the direction of flow at this end of the recess is in the substantially tangential direction of the outlet.

This invention relates to liquid displacement pumps of the kind having a body, a bladed rotor mounted within a cavity in the body, at least one inlet and one outlet at positions spaced from one another, and means for defining a part-annular recess in the Wall of the cavity of the body, said recess extending around the periphery of the rotor between the position of the inlet and that of the outlet.

The object of the invention is to provide a liquid displacement pump of the kind specified in a convenient form.

In accordance with the invention a liquid displacement pump of the kind specified is characterised in that the outlet is substantially tangential with respect to the recess and there is an abutment defining the end of the recess adjacent to the outlet, the face of the abutment defining the end of the recess being so shaped and positioned that the direction of flow between the end of the recess and the outlet is substantially in the tangential direction of the outlet.

The invention will now be described with reference to the accompanying drawings in which:

FIGURE 1 is a cross-sectional view of a pump incorporating this invention, and

FIGURE 2 is a cross-sectional view in side elevation.

The form of pump to which the invention is applied includes a body having defined therein a cavity 8 with which is mounted on a rotatable shaft 11, a rotor 9 and one wall of the cavity has defined therein a pair of arcuate recesses 12, 13. Inlets 14, communicate with the recesses respectively and substantially tangential outlets 16, 17 also communicate with the recesses 12, 13 respectively, the inlets and outlets being regularly spaced from one an- 3,459,130 Patented Aug. 5, 1969 other. The direction of rotation of the bladed rotor is indicated by the arrow 18 in the drawing.

The recesses 12, 13 are conveniently formed above the crown of an annular piston 19 which is movable in the direction of the axis of the shaft 11 so as to vary the volume of the recesses 12 and 13, and between the ends of the recesses are disposed abutments 20, 21. These abutments are so formed and positioned that in each case the face thereof which is adjacent to the outlet 16 or 17 respectively, causes the liquid to be pumped to follow the direction of the axis of the adjacent outlet. With this arrangement there is substantially no dead zone at this end of each recess in which liquid to be pumped is not Howing in the direction of the outlet. To achieve this in this example the abutments 20, 21 are of generally trapezoidal form as illustrated. Furthermore, the preferred form is so shaped that the cross-sectional area of the recess reduces towards the outlet, this reduction possibly being in more than one plane, that is in a horizontal plane, as seen in FIGURE 1 of the drawings or in a plane at right angles to this or both.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A liquid displacement pump having a body, a bladed rotor mounted within a cavity in the body, a pair of inlets and a pair of outlets, the inlets and outlets being spaced from one another, means in the body defining two part annular recesses in the wall of the body cavity at one side of the rotor, each of said recesses extending adjacent to the periphery of the rotor between the position of one of the inlets and the position of an associated outlet, the outlets being formed in a circumferential wall of the cavity, and extending substantially tangentially with respect to said wall, and a pair of abutments defining the ends of the recesses, the abutments being of trapezoidal shape and providing respective sufaces to direct liquid flow between the ends of the recesses and the outlets respectively, substantially in the tangential direction of the outlets.

References Cited UNITED STATES PATENTS 2,073,014 3/1937 Jennings 103-96 2,282,569 5/1942 Fabig 103-96 2,696,789 12/ 1954 Fabig 103-96 1,920,484 8/ 1933 Siemen et al 103-96 HENRY F. RADUAZO, Primary Examiner US. Cl. X.R. 103-5, 96, 105 

